Electrolyte for lead accumulators and method of using the same



vP ul Feb. 2519 1,748,485

UNITED STATES PATENT? OFFICE MORITZ KUGEL, OF MODLING, NEAR VIENNA, AUSTRIA.

ELECTROLYTE FOR LEAD ACCUMULATORS AND METHOD OF USING THE SAME No Drawing. Application filed August 16, 1927, Serial No. 213,439, and. in Germany November 6, 1926.

' The Working instructions given with leadunaffected by deep discharges and lengthy accumulators always contain a warning tothe standing in discharged condition, and conseetl'ect that the battery is not to be discharged quently do not demand careful, skilled attendtoo low nor allowed to stand for a length of ance.

time in a discharged condition, otherwise so- It has been found that the phosphoric-acid 55 called harmful sulphation, i. e. the formation contents of the electrolyte above described. beof large crystals of lead-sulphate, will result, 'come reduced in the course of lengthy service, causing buckling and deformation in the the phosphoric acid chemically combining positive plates, the said crystals only being with, or being absorbed to a certain extent imperfectly and very gradually reconverted by the positive electrodes and the sediment at 69 into the original products during the subsethe bottom of the cell, and thus losing its quent charging periods. efficacy in preventing sulphation As, from Y The present invention is based on the dis- What has been said above, there are disadcovery of the fact that harmful sulphation vantages in considerably. increasing the quancannot occur, even when the battery is left for tity of phosphoric acid originally added to very considerable lengths of time in a deeply the electrolyte above ten grammes per litre, a discharged condition, if a slight quantity of permanent and continuous prevention of phosphoric acid is added to the electrolyte harmful sulphation may be attained by addconsisting of diluted sulphuric-acid. Ten mg in the course of operation such quantities grammes of anhydrous orthophosphoric acid of phosphoric acid as are chemically or otherper litre of electrolyte has been found satiswise absorbed by the lead peroxide i. e. mainfactory, but larger or smaller quantities may taining the proportion of approximately 10 be added without disadvantage. A c0ngrammes of phosphoric acid to one litre of r siderable increase would merely result in the electrolyte. This can be (1 116 by sui ably voltage and capacity of the battery being reacidulating the water added to replenish duced somewhat. The phosphoric acid can evaporation, etc. with phosphoric acid.

be added to the electrolyte either in the form What I claim is: l of orthophosphoric, metaphosphoric or pyro- An electrolyte for lead accumulators which n phosphoric acid, as the latter two forms are consists'of dilute sulphuric acid with an addiconverted into orthophosphoric acid in the n of approximately 10 grams of phosphoric accumulator. It is, l'lOlVGl-zl, not advisable a i P r li to add phosphates to the electrolyte, as the In testimony whereof I affix my signature. cations ofthe alkaline or ammoniacal salt in MORITZ KUGEL- question reduce the useful life of the battery plates. It is on the other hand, permissible to employ lead phosphate alone as active material fpr making the plates, or to mix it with lead oxides, as well as to work lead oxides and phosphoric acid up into a workable .paste which will harden, provided the plates thus produced remain continuously in the same electrolyte in which they are formed, which naturally contains the phosphoric acid origi- 45 nally contained in the active material of the plates.

' Accumulators provided with electrolyte as described in this invention present a great -practical advantage compared with those hitherto employed, for, as a result of the ab- 7 I sence of all harmful sulphation, they are quite 

